1. Technical Field
The present disclosure generally relates to optical devices, and particularly to an optical lens and a light source module which has the optical lens.
2. Description of Related Art
In recent years, thanks to excellent light quality and high luminous efficiency, light emitting diodes (LEDs) have increasingly been used as substitutes for incandescent bulbs, compact fluorescent lamps and fluorescent tubes as light sources of illumination devices.
Generally, a conventional light source module includes a lens arranged above the light source to adjust an angular distribution of the light radiated from the light source. A conventional lens includes two curved surfaces, respectively designated as a small curved surface adjacent to the light source and a big curved surface away from the light source. The big curved surface covers the small curved surface therein. A top portion of the small curved surface away from the light source is configured tine-shaped to diverge light radiated from the light source from a center portion to lateral sides of the lens, thereby decreasing a light intensity at the center portion of the lens. However, a curvature of the top portion is so great that the tined top portion is hard to form, which undesirably results in a complex manufacturing.
Therefore, it is necessary to provide an optical lens and a light source module having the optical lens to overcome the above-mentioned shortcomings.